Robert L. Hobbs enjoyed a law enforcement and prosecution career lasting over four decades. Beginning in 1977, Robert served with the Jefferson County Sheriff's Department as a Corrections Officer, District Court Bailiff, and Patrol Officer. In 1981, he transferred to the Jefferson County Criminal District Attorney's Office as a Criminal Investigator.

Like many in law enforcement, he attended college part-time and in 1987, graduated from Lamar University with a bachelor's degree in criminal justice. He returned to the Sheriff's Department in 1992, serving as a Supervisor in Internal Affairs Division, and from 1992-1996, served as the Commander and Project Director of the federally funded Jefferson County Narcotics Task Force with dedicated officers from seven local police agencies.

In 1996, Robert received his Doctor of Jurisprudence degree from the South Texas College of Law - Houston. Robert then returned to the Jefferson County Criminal District Attorney's Office, serving as an Assistant District Attorney in the Trial Division litigating the entire range of criminal offense from misdemeanors to murder cases. In 1999, he entered federal service as an Assistant United States Attorney for the Eastern District of Texas where he served in the General Crimes Section, the Organized Crime Drug Enforcement Task Force (OCDETF), Lead OCDETF Attorney, and Deputy Criminal Chief and Attorney in Charge of the Beaumont and Lufkin Divisions.

In 2013, Robert was nominated by President Barack Obama to serve as the United States Marshal for the Eastern District of Texas. He was confirmed unanimously by the U.S. Senate in February 2013 and served his four-year term ending in 2017. He later returned for a twelve month term appointment as an Assistant U.S. Attorney and retired in October 2019.